21190930 has 8 divisors (see below), whose sum is σ = 38143692. Its totient is φ = 8476368.

The previous prime is 21190919. The next prime is 21190933. The reversal of 21190930 is 3909112.

It can be written as a sum of positive squares in 2 ways, for example, as 20529961 + 660969 = 4531^2 + 813^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21190895 and 21190904.

It is not an unprimeable number, because it can be changed into a prime (21190933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1059537 + ... + 1059556.

Almost surely, 2^21190930 is an apocalyptic number.

21190930 is a deficient number, since it is larger than the sum of its proper divisors (16952762).

21190930 is a wasteful number, since it uses less digits than its factorization.

21190930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2119100.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 21190930 is about 4603.3607288589. The cubic root of 21190930 is about 276.7260255533.

The spelling of 21190930 in words is "twenty-one million, one hundred ninety thousand, nine hundred thirty".